wayland: reimplement maximize and restore

[devmatteini]

Hi!

Reimplement maximize and restore features for wayland.
It was removed with wayland reimplementation in #4777. I backported maximize and restore as before that PR was merged.

It partially fixes #6203, but I didn't check toggle_fullscreen behavior.

The only issue that I noticed is that sometimes after you invoke win:restore() wezterm window doesn't restore until you focus another application.

Configuration file for tests:

local wezterm = require "wezterm"

local config = {}

wezterm.on("gui-startup", function()
  local mux = wezterm.mux
  local tab, main_pane, main_window = mux.spawn_window {}
  main_window:gui_window():maximize()
end)

config.keys = {
  {
    key = "r",
    mods = "CTRL|SHIFT",
    action = wezterm.action_callback(function(win, pane)
      wezterm.log_info 'Restore window'
      win:restore()
    end),
  },
  {
    key = "m",
    mods = "CTRL|SHIFT",
    action = wezterm.action_callback(function(win, pane)
      wezterm.log_info 'Maximize window'
      win:maximize()
    end),
  },
}

return config

Tested on Ubuntu 24.04.1 with GNOME 46.